addslashes not working for $_GET single quotes - php

Question

I'm having issues with apostrophes in GET arrays. I can't seem to escape single quotes. I've trawled through similar SO topics for over a day now with no luck. I think this may be something to do with my connection to the database as if I make a plain unconnected php page both addslashes and str_replace successfully escape single quotes in GET variables (mysqli_real_escape_string doesn't since there is no database connection).
PHP 5.2.17
Mysql 5.5.23
Magic_quotes is off
The connection:
DEFINE ('database', 'dbname');
DEFINE ('user', 'dbusername');
DEFINE ('pass', 'dbpassword');
DEFINE ('host', 'localhost');
$dbc = #mysqli_connect (host, user, pass, database) OR die ('Could not connect to database: ' . mysqli_connect_error() );
The database appears to be connected, select queries involving GET variables that do not have single quotes in work fine. However, now when a GET containing a single quote is passed, I can't seem to escape it.
print_r($_GET);
echo "<br><br>";
$text = "O'Reilly";
echo "Normal variable called text: " . $text . "<br>
addslashes(): " . addslashes($text) . "<br>
mysqli_real_escape_string(): " . mysqli_real_escape_string($dbc, $text) . "<br>
str_replace(): " . str_replace("'", "\'", $text) . "<br>
<br>";
echo "_GET variable: " . $_GET['breed'] . "<br>
addslashes(): " . addslashes($_GET['breed']) . "<br>
mysqli_real_escape_string(): " . mysqli_real_escape_string($dbc, $_GET['breed']) . "<br>
str_replace(): " . str_replace("'", "\'", $_GET['breed']) . "<br>
<br>";
$_GET['breed'] = "O'Conner";
echo "_GET variable with new value: " . $_GET['breed'] . "<br>
addslashes(): " . addslashes($_GET['breed']) . "<br>
mysqli_real_escape_string(): " . mysqli_real_escape_string($dbc, $_GET['breed']) . "<br>
str_replace(): " . str_replace("'", "\'", $_GET['breed']) . "<br>
<br>";
gives:
Array ( [breed] => Cirneco dell'Etna )
Normal variable called text: O'Reilly
addslashes(): O\'Reilly
mysqli_real_escape_string(): O\'Reilly
str_replace(): O\'Reilly
_GET variable: Cirneco dell'Etna
addslashes(): Cirneco dell'Etna
mysqli_real_escape_string(): Cirneco dell'Etna
str_replace(): Cirneco dell'Etna
_GET variable with new value: O'Conner
addslashes(): O\'Conner
mysqli_real_escape_string(): O\'Conner
str_replace(): O\'Conner
The single quote in Cirneco dell'Etna is definitely a single quote, not ` etc. I also tried urlencode() and urldecode() - it replaced spaces with + but did not escape the single quotes. The GETs need single quotes to make user-friendly URLs - usernames and (in this case) breed names for example; Cirneco dell%39Etna is not intuitive. It's not a complex site at all but single quotes crop up a lot as ownership is a major part of the site, so I'd like to work out what's happening!
I have tried switching to PDO but found it beyond me - I'm a novice programmer and my attempt at PDO was mind-boggling to troubleshoot - I can't tell whether errors in PDO are my typos, or a continuation of this same issue.
Many thanks.
EDIT
The select query (which works as expected for _GET variables without single quotes in) is constructed as follows:
$q = "SELECT breed_name, breed_type from b_breed
where breed_name = '" . $_GET['breed'] . "'
LIMIT 1";
$result = mysqli_query($dbc,$q);
if($result->num_rows == 0)
{
}
else
{
$row_breed = mysqli_fetch_array($result, MYSQLI_ASSOC);
{
echo "<h1>" . $row_breed['breed_name'] . " - " . $row_breed['breed_type'] . "</h1>";
}
}
I have tried including addslashes, mysqli_real_escape_string and str_replace (not at the same time) with the $_GET within the query, to no effect. If I echo $q, the single quote is never escaped.
SELECT breed_name, breed_type from b_breed where breed_name = 'Cirneco dell'Etna' LIMIT 1
Oddly, if I switch the double and single quotes so I have:
$q = 'SELECT breed_name, breed_type from b_breed
where breed_name = "' . $_GET['breed'] . '"
LIMIT 1';
SELECT breed_name, breed_type from b_breed where breed_name = "Cirneco dell'Etna" LIMIT 1
It still returns no rows on the page, although the echoed $q will return rows in PHPMyAdmin.
EDIT Solved!
It was changing the ' in the database to an ASCII character. Adding the following converted it back to ', which could then be escaped:
$_GET['breed'] = htmlspecialchars_decode($_GET['breed'], ENT_QUOTES);

Answer 1

You can check what are You getting from GET
try
$string = $_GET['breed'];
for ($i=0;$i<strlen($string);$i++) {
echo '<br>'.$string[$i].' : '.ord($string[$i]);
}